Bottom Line:
FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl.FTO silence has no effect on insulin secretion of MIN6 cells.Furthermore, reactive oxygen species (ROS) production and NF-κB activation are significantly promoted by FTO overexpression.

ABSTRACTFTO (Fat mass and obesity-associated) is associated with increased risk of obesity and type 2 diabetes incurrence. Pancreas islet β cells dysfunction and insulin resistance are major causes of type 2 diabetes. However, whether FTO plays an important functional role in pancreatic β cells as well as the related molecular mechanism is still unclear. In the present study, the tissue expression profile of FTO was firstly determined using quantitative PCR and western blot. FTO is widely expressed in various tissues and presented with relative high expression in pancreas tissue, especially in endocrine pancreas. FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl. FTO silence has no effect on insulin secretion of MIN6 cells. However, FTO overexpression doesn't affect the transcription of insulin gene. Furthermore, reactive oxygen species (ROS) production and NF-κB activation are significantly promoted by FTO overexpression. Inhibition of intracellular ROS production by N-acetyl-L-cysteine (NAC) can alleviate NF-κB activation and restore the insulin secretion mediated by FTO overexpression. A whole transcript-microarray is employed to analyze the differential gene expression mediated by FTO overexpression. The genes which are modulated by FTO are involved in many important biological pathways such as G-protein coupled receptor signaling and NF-κB signaling. Therefore, our study indicates that FTO may contribute to pancreas islet β cells dysfunction and the inhibition of FTO activity is a potential target for the treatment of diabetes.

Mentions:
To investigate the mechanism that FTO regulates the insulin secretion, we determined the mRNA level of insulin 1 and insulin 2 in MIN6 cells stably overexpressed pLVX-IRES-ZsGreen-FTO or pLVX-IRES-ZsGreen using QPCR. Both the expression of insulin 1 and 2 are not affected by FTO overexpression compared with that in control group (Fig 3A and 3B).

Mentions:
To investigate the mechanism that FTO regulates the insulin secretion, we determined the mRNA level of insulin 1 and insulin 2 in MIN6 cells stably overexpressed pLVX-IRES-ZsGreen-FTO or pLVX-IRES-ZsGreen using QPCR. Both the expression of insulin 1 and 2 are not affected by FTO overexpression compared with that in control group (Fig 3A and 3B).

Bottom Line:
FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl.FTO silence has no effect on insulin secretion of MIN6 cells.Furthermore, reactive oxygen species (ROS) production and NF-κB activation are significantly promoted by FTO overexpression.

ABSTRACTFTO (Fat mass and obesity-associated) is associated with increased risk of obesity and type 2 diabetes incurrence. Pancreas islet β cells dysfunction and insulin resistance are major causes of type 2 diabetes. However, whether FTO plays an important functional role in pancreatic β cells as well as the related molecular mechanism is still unclear. In the present study, the tissue expression profile of FTO was firstly determined using quantitative PCR and western blot. FTO is widely expressed in various tissues and presented with relative high expression in pancreas tissue, especially in endocrine pancreas. FTO overexpression in MIN6 cells achieved by lentivirus delivery significantly inhibits insulin secretion in the presence of glucose stimulus as well as KCl. FTO silence has no effect on insulin secretion of MIN6 cells. However, FTO overexpression doesn't affect the transcription of insulin gene. Furthermore, reactive oxygen species (ROS) production and NF-κB activation are significantly promoted by FTO overexpression. Inhibition of intracellular ROS production by N-acetyl-L-cysteine (NAC) can alleviate NF-κB activation and restore the insulin secretion mediated by FTO overexpression. A whole transcript-microarray is employed to analyze the differential gene expression mediated by FTO overexpression. The genes which are modulated by FTO are involved in many important biological pathways such as G-protein coupled receptor signaling and NF-κB signaling. Therefore, our study indicates that FTO may contribute to pancreas islet β cells dysfunction and the inhibition of FTO activity is a potential target for the treatment of diabetes.